The present invention is directed to spinal implants, and more particularly, spinal fusion implants.
The deterioration of vertebral bodies and/or vertebral discs is a major cause of back and neck pain in many patients. Through the years, many different techniques for restoring the natural anatomical spacing in the spine and thereby alleviating this pain have been developed and practiced by surgeons. For instance, implants and techniques for implanting such implants have been designed to preserve motion between adjacent vertebral bodies. These motion preserving implants are adapted to emulate a removed spinal disc. Examples of such implants (and the methods of implanting same) are disclosed in U.S. Pat. No. 6,989,032 (“the '032 patent”) and U.S. Pat. No. 7,169,182 (“the '182 patent”), the disclosures of which are hereby incorporated by reference herein. Nonetheless, even given the success of such motion preserving devices, it is still sometimes necessary to fuse adjacent vertebral bodies so that no movement is permitted therebetween.
Spinal fusion surgery typically involves removing the disc material from between adjacent vertebral bodies, which thereby creates an empty intervertebral space. In this space is implanted an implant or cage that is then fixably mounted to the end plates of the adjacent vertebral bodies. Bone growth is often permitted through the implant, and is in fact sometimes provoked by the placement of bone growth inducing substances within the cage. However, even given this bone growth through the cage, it is sometimes necessary to at least initially mount the cage to the vertebral bodies through the use of fixation elements such as screws. Furthermore, it has also determined that providing an angled implant or cage can aid in returning the adjacent vertebral bodies to their natural “lordotic” angle.
Even if a surgeon initially determines that he or she wishes to perform a motion preserving surgery on a patient, sometimes it becomes apparent during the procedure that a fusion procedure would benefit the patient. Likewise, surgeons often recognize the need to fuse vertebral bodies at levels adjacent to the initial one in question. Thus, it is desirable to have a fusion implant that can easily be implemented and implanted utilizing the tools and procedure used in a motion preserving surgery. Moreover, it is also desired to have such a fusion implant be easily implanted using those tools, easily affixed to the intervertebral bodies, and prevented from becoming dislodged even after just initially being implanted.
Therefore, there exists a need for an improved spinal fusion device.